Portable fan



FIG. 1 is a perspective view of the invention;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The purpose of broken lines in the drawings is to show the portions of the portable fan that form no part of the claimed design. 

CLAIM The ornamental design for a portable fan, as shown and described herein. 